Implement strStr().
Return the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack.
Input: haystack = "hello", needle = "ll"
Output: 2
Input: haystack = "aaaaa", needle = "bba"
Output: -1
class Solution:
def strStr(self, haystack, needle):
"""
:type haystack: str
:type needle: str
:rtype: int
"""
if not needle:
return 0
index = 0
n = len(needle)
i = 0
while i < len(haystack):
if haystack[i] == needle[index]:
index += 1
i += 1
if index == n:
return i - n
else:
i = i - index + 1
index = 0
return -1
class Solution:
def strStr(self, haystack, needle):
"""
:type haystack: str
:type needle: str
:rtype: int
"""
return haystack.find(needle)
